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			<h1>Python3 多线程</h1>
<p>多线程类似于同时执行多个不同程序，多线程运行有如下优点：</p>
<ul>
<li>使用线程可以把占据长时间的程序中的任务放到后台去处理。</li>
<li>用户界面可以更加吸引人，比如用户点击了一个按钮去触发某些事件的处理，可以弹出一个进度条来显示处理的进度。</li>
<li>程序的运行速度可能加快。</li>
<li>在一些等待的任务实现上如用户输入、文件读写和网络收发数据等，线程就比较有用了。在这种情况下我们可以释放一些珍贵的资源如内存占用等等。</li>
</ul>
<p>每个独立的线程有一个程序运行的入口、顺序执行序列和程序的出口。但是线程不能够独立执行，必须依存在应用程序中，由应用程序提供多个线程执行控制。
</p>
<p>每个线程都有他自己的一组CPU寄存器，称为线程的上下文，该上下文反映了线程上次运行该线程的CPU寄存器的状态。
</p><p>指令指针和堆栈指针寄存器是线程上下文中两个最重要的寄存器，线程总是在进程得到上下文中运行的，这些地址都用于标志拥有线程的进程地址空间中的内存。
</p>
<ul>

<li>线程可以被抢占（中断）。</li>
<li>在其他线程正在运行时，线程可以暂时搁置（也称为睡眠） -- 这就是线程的退让。
</li>
</ul>
<p>线程可以分为:</p>

<ul>
<li><strong>内核线程：</strong>由操作系统内核创建和撤销。</b></li>
<li><strong>用户线程：</strong>不需要内核支持而在用户程序中实现的线程。</b></li>
</ul>

<p>Python3 线程中常用的两个模块为：</p>
<ul>
<li><b>_thread</b></li>
<li><b>threading(推荐使用)</b></li>
</ul>
<p> thread 模块已被废弃。用户可以使用 threading 模块代替。所以，在 Python3 中不能再使用"thread" 模块。为了兼容性，Python3 将 thread 重命名为 "_thread"。 </p>
<br>
<h2>开始学习Python线程</h2>
<p>Python中使用线程有两种方式：函数或者用类来包装线程对象。</p>
<p>函数式：调用 _thread 模块中的start_new_thread()函数来产生新线程。语法如下:</p>
<pre>
_thread.start_new_thread ( function, args[, kwargs] )
</pre>
<p>参数说明:</p>
<ul>
<li>function - 线程函数。</li>
<li>args - 传递给线程函数的参数,他必须是个tuple类型。</li>
<li>kwargs - 可选参数。</li>
</ul>

<div class="example"><h2 class="example">实例</h2> <div class="example_code">
<span style="color: #a50">#!/usr/bin/python3</span><br />
<br />
<span style="color: Green;font-weight:bold;">import</span> _thread<br />
<span style="color: Green;font-weight:bold;">import</span> <span style="color: #05a;">time</span><br />
<br />
<span style="color: #a50"># 为线程定义一个函数</span><br />
<span style="color: Green;font-weight:bold;">def</span> print_time<span style="color: Olive;">&#40;</span> threadName<span style="color: Gray;">,</span> delay<span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp;count <span style="color: Gray;">=</span> <span style="color: Maroon;">0</span><br />
&nbsp; &nbsp;<span style="color: Green;font-weight:bold;">while</span> count <span style="color: Gray;">&lt;</span> <span style="color: Maroon;">5</span>:<br />
&nbsp; &nbsp; &nbsp; <span style="color: #05a;">time</span>.<span style="color: #05a;">sleep</span><span style="color: Olive;">&#40;</span>delay<span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; count +<span style="color: Gray;">=</span> <span style="color: Maroon;">1</span><br />
&nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;%s: %s&quot;</span> % <span style="color: Olive;">&#40;</span> threadName<span style="color: Gray;">,</span> <span style="color: #05a;">time</span>.<span style="color: #05a;">ctime</span><span style="color: Olive;">&#40;</span><span style="color: #05a;">time</span>.<span style="color: #05a;">time</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><span style="color: Olive;">&#41;</span> <span style="color: Olive;">&#41;</span><span style="color: Olive;">&#41;</span><br />
<br />
<span style="color: #a50"># 创建两个线程</span><br />
<span style="color: Green;font-weight:bold;">try</span>:<br />
&nbsp; &nbsp;_thread.<span style="color: #05a;">start_new_thread</span><span style="color: Olive;">&#40;</span> print_time<span style="color: Gray;">,</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;Thread-1&quot;</span><span style="color: Gray;">,</span> <span style="color: Maroon;">2</span><span style="color: Gray;">,</span> <span style="color: Olive;">&#41;</span> <span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp;_thread.<span style="color: #05a;">start_new_thread</span><span style="color: Olive;">&#40;</span> print_time<span style="color: Gray;">,</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;Thread-2&quot;</span><span style="color: Gray;">,</span> <span style="color: Maroon;">4</span><span style="color: Gray;">,</span> <span style="color: Olive;">&#41;</span> <span style="color: Olive;">&#41;</span><br />
<span style="color: Green;font-weight:bold;">except</span>:<br />
&nbsp; &nbsp;<span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;Error: 无法启动线程&quot;</span><span style="color: Olive;">&#41;</span><br />
<br />
<span style="color: Green;font-weight:bold;">while</span> <span style="color: Maroon;">1</span>:<br />
&nbsp; &nbsp;<span style="color: Green;font-weight:bold;">pass</span><br />
</div></div>

<p>执行以上程序输出结果如下：</p>
<pre>
Thread-1: Wed Jan  5 17:38:08 2022
Thread-2: Wed Jan  5 17:38:10 2022
Thread-1: Wed Jan  5 17:38:10 2022
Thread-1: Wed Jan  5 17:38:12 2022
Thread-2: Wed Jan  5 17:38:14 2022
Thread-1: Wed Jan  5 17:38:14 2022
Thread-1: Wed Jan  5 17:38:16 2022
Thread-2: Wed Jan  5 17:38:18 2022
Thread-2: Wed Jan  5 17:38:22 2022
Thread-2: Wed Jan  5 17:38:26 2022
</pre>
<p>执行以上程后可以按下 ctrl-c 退出。</p>


<p>
<hr>
<h2>线程模块</h2>
<p>Python3 通过两个标准库 _thread 和 threading 提供对线程的支持。</p><p>
_thread 提供了低级别的、原始的线程以及一个简单的锁，它相比于 threading 模块的功能还是比较有限的。</p>
<p>threading 模块除了包含 _thread 模块中的所有方法外，还提供的其他方法： </p>
<ul>
<li>threading.currentThread(): 返回当前的线程变量。 </li>
<li>threading.enumerate(): 返回一个包含正在运行的线程的list。正在运行指线程启动后、结束前，不包括启动前和终止后的线程。 </li>
<li>threading.activeCount(): 返回正在运行的线程数量，与len(threading.enumerate())有相同的结果。</li>
</ul>
<p>除了使用方法外，线程模块同样提供了Thread类来处理线程，Thread类提供了以下方法:</p>
<ul>
<li><b>run():</b> 用以表示线程活动的方法。</li>
<li><b>start():</b>启动线程活动。</p></li>
<li><b> join([time]):</b> 等待至线程中止。这阻塞调用线程直至线程的join() 方法被调用中止-正常退出或者抛出未处理的异常-或者是可选的超时发生。</li>
<li><b> isAlive():</b> 返回线程是否活动的。</li>
<li><b> getName():</b> 返回线程名。</li>
<li><b> setName():</b> 设置线程名。</li>
</ul>
<hr>
<h2>使用 threading 模块创建线程</h2>
<p>我们可以通过直接从 threading.Thread 继承创建一个新的子类，并实例化后调用 start() 方法启动新线程，即它调用了线程的 run()  方法：</p>

<div class="example"><h2 class="example">实例</h2> <div class="example_code">
<span style="color: #a50">#!/usr/bin/python3</span><br />
<br />
<span style="color: Green;font-weight:bold;">import</span> <span style="color: #05a;">threading</span><br />
<span style="color: Green;font-weight:bold;">import</span> <span style="color: #05a;">time</span><br />
<br />
exitFlag <span style="color: Gray;">=</span> <span style="color: Maroon;">0</span><br />
<br />
<span style="color: Green;font-weight:bold;">class</span> myThread <span style="color: Olive;">&#40;</span><span style="color: #05a;">threading</span>.<span style="color: #05a;">Thread</span><span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; <span style="color: Green;font-weight:bold;">def</span> <span style="color: Navy;">__init__</span><span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span><span style="color: Gray;">,</span> threadID<span style="color: Gray;">,</span> name<span style="color: Gray;">,</span> delay<span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: #05a;">threading</span>.<span style="color: #05a;">Thread</span>.<span style="color: Navy;">__init__</span><span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Teal;">self</span>.<span style="color: #05a;">threadID</span> <span style="color: Gray;">=</span> threadID<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Teal;">self</span>.<span style="color: #05a;">name</span> <span style="color: Gray;">=</span> name<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Teal;">self</span>.<span style="color: #05a;">delay</span> <span style="color: Gray;">=</span> delay<br />
&nbsp; &nbsp; <span style="color: Green;font-weight:bold;">def</span> run<span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span><span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;开始线程：&quot;</span> + <span style="color: Teal;">self</span>.<span style="color: #05a;">name</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; print_time<span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span>.<span style="color: #05a;">name</span><span style="color: Gray;">,</span> <span style="color: Teal;">self</span>.<span style="color: #05a;">delay</span><span style="color: Gray;">,</span> <span style="color: Maroon;">5</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;退出线程：&quot;</span> + <span style="color: Teal;">self</span>.<span style="color: #05a;">name</span><span style="color: Olive;">&#41;</span><br />
<br />
<span style="color: Green;font-weight:bold;">def</span> print_time<span style="color: Olive;">&#40;</span>threadName<span style="color: Gray;">,</span> delay<span style="color: Gray;">,</span> counter<span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; <span style="color: Green;font-weight:bold;">while</span> counter:<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">if</span> exitFlag:<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; threadName.<span style="color: #05a;">exit</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: #05a;">time</span>.<span style="color: #05a;">sleep</span><span style="color: Olive;">&#40;</span>delay<span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;%s: %s&quot;</span> % <span style="color: Olive;">&#40;</span>threadName<span style="color: Gray;">,</span> <span style="color: #05a;">time</span>.<span style="color: #05a;">ctime</span><span style="color: Olive;">&#40;</span><span style="color: #05a;">time</span>.<span style="color: #05a;">time</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><span style="color: Olive;">&#41;</span><span style="color: Olive;">&#41;</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; counter -<span style="color: Gray;">=</span> <span style="color: Maroon;">1</span><br />
<br />
<span style="color: #a50"># 创建新线程</span><br />
thread1 <span style="color: Gray;">=</span> myThread<span style="color: Olive;">&#40;</span><span style="color: Maroon;">1</span><span style="color: Gray;">,</span> <span style="color: #a11;">&quot;Thread-1&quot;</span><span style="color: Gray;">,</span> <span style="color: Maroon;">1</span><span style="color: Olive;">&#41;</span><br />
thread2 <span style="color: Gray;">=</span> myThread<span style="color: Olive;">&#40;</span><span style="color: Maroon;">2</span><span style="color: Gray;">,</span> <span style="color: #a11;">&quot;Thread-2&quot;</span><span style="color: Gray;">,</span> <span style="color: Maroon;">2</span><span style="color: Olive;">&#41;</span><br />
<br />
<span style="color: #a50"># 开启新线程</span><br />
thread1.<span style="color: #05a;">start</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
thread2.<span style="color: #05a;">start</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
thread1.<span style="color: #05a;">join</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
thread2.<span style="color: #05a;">join</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
<span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;退出主线程&quot;</span><span style="color: Olive;">&#41;</span><br />
</div></div>
<p>以上程序执行结果如下；</p>
<pre>
开始线程：Thread-1
开始线程：Thread-2
Thread-1: Wed Jan  5 17:34:54 2022
Thread-2: Wed Jan  5 17:34:55 2022
Thread-1: Wed Jan  5 17:34:55 2022
Thread-1: Wed Jan  5 17:34:56 2022
Thread-2: Wed Jan  5 17:34:57 2022
Thread-1: Wed Jan  5 17:34:57 2022
Thread-1: Wed Jan  5 17:34:58 2022
退出线程：Thread-1
Thread-2: Wed Jan  5 17:34:59 2022
Thread-2: Wed Jan  5 17:35:01 2022
Thread-2: Wed Jan  5 17:35:03 2022
退出线程：Thread-2
退出主线程
</pre>
<hr>
<h2>线程同步</h2>
<p>如果多个线程共同对某个数据修改，则可能出现不可预料的结果，为了保证数据的正确性，需要对多个线程进行同步。
</p>
<p>
使用 Thread 对象的 Lock 和 Rlock 可以实现简单的线程同步，这两个对象都有 acquire 方法和 release 方法，对于那些需要每次只允许一个线程操作的数据，可以将其操作放到 acquire 和 release 方法之间。如下：
</p>
<p>多线程的优势在于可以同时运行多个任务（至少感觉起来是这样）。但是当线程需要共享数据时，可能存在数据不同步的问题。</p>
<p>
考虑这样一种情况：一个列表里所有元素都是0，线程"set"从后向前把所有元素改成1，而线程"print"负责从前往后读取列表并打印。</p>
<p>
那么，可能线程"set"开始改的时候，线程"print"便来打印列表了，输出就成了一半0一半1，这就是数据的不同步。为了避免这种情况，引入了锁的概念。
</p>
<p>
锁有两种状态——锁定和未锁定。每当一个线程比如"set"要访问共享数据时，必须先获得锁定；如果已经有别的线程比如"print"获得锁定了，那么就让线程"set"暂停，也就是同步阻塞；等到线程"print"访问完毕，释放锁以后，再让线程"set"继续。
</p>
<p>
经过这样的处理，打印列表时要么全部输出0，要么全部输出1，不会再出现一半0一半1的尴尬场面。</p>

<div class="example"><h2 class="example">实例</h2> <div class="example_code">
<span style="color: #a50">#!/usr/bin/python3</span><br />
<br />
<span style="color: Green;font-weight:bold;">import</span> <span style="color: #05a;">threading</span><br />
<span style="color: Green;font-weight:bold;">import</span> <span style="color: #05a;">time</span><br />
<br />
<span style="color: Green;font-weight:bold;">class</span> myThread <span style="color: Olive;">&#40;</span><span style="color: #05a;">threading</span>.<span style="color: #05a;">Thread</span><span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; <span style="color: Green;font-weight:bold;">def</span> <span style="color: Navy;">__init__</span><span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span><span style="color: Gray;">,</span> threadID<span style="color: Gray;">,</span> name<span style="color: Gray;">,</span> delay<span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: #05a;">threading</span>.<span style="color: #05a;">Thread</span>.<span style="color: Navy;">__init__</span><span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Teal;">self</span>.<span style="color: #05a;">threadID</span> <span style="color: Gray;">=</span> threadID<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Teal;">self</span>.<span style="color: #05a;">name</span> <span style="color: Gray;">=</span> name<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Teal;">self</span>.<span style="color: #05a;">delay</span> <span style="color: Gray;">=</span> delay<br />
&nbsp; &nbsp; <span style="color: Green;font-weight:bold;">def</span> run<span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span><span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;开启线程： &quot;</span> + <span style="color: Teal;">self</span>.<span style="color: #05a;">name</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: #a50"># 获取锁，用于线程同步</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; threadLock.<span style="color: #05a;">acquire</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; print_time<span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span>.<span style="color: #05a;">name</span><span style="color: Gray;">,</span> <span style="color: Teal;">self</span>.<span style="color: #05a;">delay</span><span style="color: Gray;">,</span> <span style="color: Maroon;">3</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: #a50"># 释放锁，开启下一个线程</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; threadLock.<span style="color: #05a;">release</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
<br />
<span style="color: Green;font-weight:bold;">def</span> print_time<span style="color: Olive;">&#40;</span>threadName<span style="color: Gray;">,</span> delay<span style="color: Gray;">,</span> counter<span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; <span style="color: Green;font-weight:bold;">while</span> counter:<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: #05a;">time</span>.<span style="color: #05a;">sleep</span><span style="color: Olive;">&#40;</span>delay<span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;%s: %s&quot;</span> % <span style="color: Olive;">&#40;</span>threadName<span style="color: Gray;">,</span> <span style="color: #05a;">time</span>.<span style="color: #05a;">ctime</span><span style="color: Olive;">&#40;</span><span style="color: #05a;">time</span>.<span style="color: #05a;">time</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><span style="color: Olive;">&#41;</span><span style="color: Olive;">&#41;</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; counter -<span style="color: Gray;">=</span> <span style="color: Maroon;">1</span><br />
<br />
threadLock <span style="color: Gray;">=</span> <span style="color: #05a;">threading</span>.<span style="color: #05a;">Lock</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
threads <span style="color: Gray;">=</span> <span style="color: Olive;">&#91;</span><span style="color: Olive;">&#93;</span><br />
<br />
<span style="color: #a50"># 创建新线程</span><br />
thread1 <span style="color: Gray;">=</span> myThread<span style="color: Olive;">&#40;</span><span style="color: Maroon;">1</span><span style="color: Gray;">,</span> <span style="color: #a11;">&quot;Thread-1&quot;</span><span style="color: Gray;">,</span> <span style="color: Maroon;">1</span><span style="color: Olive;">&#41;</span><br />
thread2 <span style="color: Gray;">=</span> myThread<span style="color: Olive;">&#40;</span><span style="color: Maroon;">2</span><span style="color: Gray;">,</span> <span style="color: #a11;">&quot;Thread-2&quot;</span><span style="color: Gray;">,</span> <span style="color: Maroon;">2</span><span style="color: Olive;">&#41;</span><br />
<br />
<span style="color: #a50"># 开启新线程</span><br />
thread1.<span style="color: #05a;">start</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
thread2.<span style="color: #05a;">start</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
<br />
<span style="color: #a50"># 添加线程到线程列表</span><br />
threads.<span style="color: #05a;">append</span><span style="color: Olive;">&#40;</span>thread1<span style="color: Olive;">&#41;</span><br />
threads.<span style="color: #05a;">append</span><span style="color: Olive;">&#40;</span>thread2<span style="color: Olive;">&#41;</span><br />
<br />
<span style="color: #a50"># 等待所有线程完成</span><br />
<span style="color: Green;font-weight:bold;">for</span> t <span style="color: Green;font-weight:bold;">in</span> threads:<br />
&nbsp; &nbsp; t.<span style="color: #05a;">join</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
<span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;退出主线程&quot;</span><span style="color: Olive;">&#41;</span><br />
</div></div>
<p>执行以上程序，输出结果为：</p>
<pre>
开启线程： Thread-1
开启线程： Thread-2
Thread-1: Wed Jan  5 17:36:50 2022
Thread-1: Wed Jan  5 17:36:51 2022
Thread-1: Wed Jan  5 17:36:52 2022
Thread-2: Wed Jan  5 17:36:54 2022
Thread-2: Wed Jan  5 17:36:56 2022
Thread-2: Wed Jan  5 17:36:58 2022
退出主线程
</pre>
<hr>
<h2>线程优先级队列（ Queue）
</h2>
<p>Python 的 Queue 模块中提供了同步的、线程安全的队列类，包括FIFO（先入先出)队列Queue，LIFO（后入先出）队列LifoQueue，和优先级队列 PriorityQueue。
</p><p>这些队列都实现了锁原语，能够在多线程中直接使用，可以使用队列来实现线程间的同步。</p>

<p>Queue 模块中的常用方法:<p>
<ul>
<li>Queue.qsize() 返回队列的大小 </li>
<li>Queue.empty() 如果队列为空，返回True,反之False </li>
<li>Queue.full() 如果队列满了，返回True,反之False</li>
<li>Queue.full 与 maxsize 大小对应 </li>
<li>Queue.get([block[, timeout]])获取队列，timeout等待时间 </li>
<li>Queue.get_nowait() 相当Queue.get(False)</li>
<li>Queue.put(item) 写入队列，timeout等待时间 </li>
<li>Queue.put_nowait(item) 相当Queue.put(item, False)</li>
<li>Queue.task_done() 在完成一项工作之后，Queue.task_done()函数向任务已经完成的队列发送一个信号</li>
<li>Queue.join() 实际上意味着等到队列为空，再执行别的操作</li>
</ul>

<div class="example"><h2 class="example">实例</h2> <div class="example_code">
<span style="color: #a50">#!/usr/bin/python3</span><br />
<br />
<span style="color: Green;font-weight:bold;">import</span> queue<br />
<span style="color: Green;font-weight:bold;">import</span> <span style="color: #05a;">threading</span><br />
<span style="color: Green;font-weight:bold;">import</span> <span style="color: #05a;">time</span><br />
<br />
exitFlag <span style="color: Gray;">=</span> <span style="color: Maroon;">0</span><br />
<br />
<span style="color: Green;font-weight:bold;">class</span> myThread <span style="color: Olive;">&#40;</span><span style="color: #05a;">threading</span>.<span style="color: #05a;">Thread</span><span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; <span style="color: Green;font-weight:bold;">def</span> <span style="color: Navy;">__init__</span><span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span><span style="color: Gray;">,</span> threadID<span style="color: Gray;">,</span> name<span style="color: Gray;">,</span> q<span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: #05a;">threading</span>.<span style="color: #05a;">Thread</span>.<span style="color: Navy;">__init__</span><span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Teal;">self</span>.<span style="color: #05a;">threadID</span> <span style="color: Gray;">=</span> threadID<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Teal;">self</span>.<span style="color: #05a;">name</span> <span style="color: Gray;">=</span> name<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Teal;">self</span>.<span style="color: #05a;">q</span> <span style="color: Gray;">=</span> q<br />
&nbsp; &nbsp; <span style="color: Green;font-weight:bold;">def</span> run<span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span><span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;开启线程：&quot;</span> + <span style="color: Teal;">self</span>.<span style="color: #05a;">name</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; process_data<span style="color: Olive;">&#40;</span><span style="color: Teal;">self</span>.<span style="color: #05a;">name</span><span style="color: Gray;">,</span> <span style="color: Teal;">self</span>.<span style="color: #05a;">q</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;退出线程：&quot;</span> + <span style="color: Teal;">self</span>.<span style="color: #05a;">name</span><span style="color: Olive;">&#41;</span><br />
<br />
<span style="color: Green;font-weight:bold;">def</span> process_data<span style="color: Olive;">&#40;</span>threadName<span style="color: Gray;">,</span> q<span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; <span style="color: Green;font-weight:bold;">while</span> <span style="color: Green;font-weight:bold;">not</span> exitFlag:<br />
&nbsp; &nbsp; &nbsp; &nbsp; queueLock.<span style="color: #05a;">acquire</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">if</span> <span style="color: Green;font-weight:bold;">not</span> workQueue.<span style="color: #05a;">empty</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; data <span style="color: Gray;">=</span> q.<span style="color: #05a;">get</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; queueLock.<span style="color: #05a;">release</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;%s processing %s&quot;</span> % <span style="color: Olive;">&#40;</span>threadName<span style="color: Gray;">,</span> data<span style="color: Olive;">&#41;</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: Green;font-weight:bold;">else</span>:<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; queueLock.<span style="color: #05a;">release</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; <span style="color: #05a;">time</span>.<span style="color: #05a;">sleep</span><span style="color: Olive;">&#40;</span><span style="color: Maroon;">1</span><span style="color: Olive;">&#41;</span><br />
<br />
threadList <span style="color: Gray;">=</span> <span style="color: Olive;">&#91;</span><span style="color: #a11;">&quot;Thread-1&quot;</span><span style="color: Gray;">,</span> <span style="color: #a11;">&quot;Thread-2&quot;</span><span style="color: Gray;">,</span> <span style="color: #a11;">&quot;Thread-3&quot;</span><span style="color: Olive;">&#93;</span><br />
nameList <span style="color: Gray;">=</span> <span style="color: Olive;">&#91;</span><span style="color: #a11;">&quot;One&quot;</span><span style="color: Gray;">,</span> <span style="color: #a11;">&quot;Two&quot;</span><span style="color: Gray;">,</span> <span style="color: #a11;">&quot;Three&quot;</span><span style="color: Gray;">,</span> <span style="color: #a11;">&quot;Four&quot;</span><span style="color: Gray;">,</span> <span style="color: #a11;">&quot;Five&quot;</span><span style="color: Olive;">&#93;</span><br />
queueLock <span style="color: Gray;">=</span> <span style="color: #05a;">threading</span>.<span style="color: #05a;">Lock</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
workQueue <span style="color: Gray;">=</span> queue.<span style="color: #05a;">Queue</span><span style="color: Olive;">&#40;</span><span style="color: Maroon;">10</span><span style="color: Olive;">&#41;</span><br />
threads <span style="color: Gray;">=</span> <span style="color: Olive;">&#91;</span><span style="color: Olive;">&#93;</span><br />
threadID <span style="color: Gray;">=</span> <span style="color: Maroon;">1</span><br />
<br />
<span style="color: #a50"># 创建新线程</span><br />
<span style="color: Green;font-weight:bold;">for</span> tName <span style="color: Green;font-weight:bold;">in</span> threadList:<br />
&nbsp; &nbsp; <span style="color: #05a;">thread</span> <span style="color: Gray;">=</span> myThread<span style="color: Olive;">&#40;</span>threadID<span style="color: Gray;">,</span> tName<span style="color: Gray;">,</span> workQueue<span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; <span style="color: #05a;">thread</span>.<span style="color: #05a;">start</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; threads.<span style="color: #05a;">append</span><span style="color: Olive;">&#40;</span><span style="color: #05a;">thread</span><span style="color: Olive;">&#41;</span><br />
&nbsp; &nbsp; threadID +<span style="color: Gray;">=</span> <span style="color: Maroon;">1</span><br />
<br />
<span style="color: #a50"># 填充队列</span><br />
queueLock.<span style="color: #05a;">acquire</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
<span style="color: Green;font-weight:bold;">for</span> word <span style="color: Green;font-weight:bold;">in</span> nameList:<br />
&nbsp; &nbsp; workQueue.<span style="color: #05a;">put</span><span style="color: Olive;">&#40;</span>word<span style="color: Olive;">&#41;</span><br />
queueLock.<span style="color: #05a;">release</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
<br />
<span style="color: #a50"># 等待队列清空</span><br />
<span style="color: Green;font-weight:bold;">while</span> <span style="color: Green;font-weight:bold;">not</span> workQueue.<span style="color: #05a;">empty</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span>:<br />
&nbsp; &nbsp; <span style="color: Green;font-weight:bold;">pass</span><br />
<br />
<span style="color: #a50"># 通知线程是时候退出</span><br />
exitFlag <span style="color: Gray;">=</span> <span style="color: Maroon;">1</span><br />
<br />
<span style="color: #a50"># 等待所有线程完成</span><br />
<span style="color: Green;font-weight:bold;">for</span> t <span style="color: Green;font-weight:bold;">in</span> threads:<br />
&nbsp; &nbsp; t.<span style="color: #05a;">join</span><span style="color: Olive;">&#40;</span><span style="color: Olive;">&#41;</span><br />
<span style="color: Green;font-weight:bold;">print</span> <span style="color: Olive;">&#40;</span><span style="color: #a11;">&quot;退出主线程&quot;</span><span style="color: Olive;">&#41;</span><br />
</div></div>

<p>以上程序执行结果：</p>

<pre>
开启线程：Thread-1
开启线程：Thread-2
开启线程：Thread-3
Thread-3 processing One
Thread-1 processing Two
Thread-2 processing Three
Thread-3 processing Four
Thread-1 processing Five
退出线程：Thread-3
退出线程：Thread-2
退出线程：Thread-1
退出主线程
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<div id="postcomments"  style="display:none;" >
	<ol class="commentlist">
		<li class="comment even thread-even depth-1" id="comment-45570"><span class="comt-f">#0</span><div class="comt-avatar wrapper"><i style="font-size:36px;" class="fa fa-user-circle" aria-hidden="true"></i><div class="tooltip"><p><i class="fa fa-user" aria-hidden="true"></i>&nbsp;&nbsp;&nbsp;Dexu</p><p><i class="fa fa-envelope" aria-hidden="true"></i>&nbsp;&nbsp;724***971@qq.com</p></div><div id="runoobvote-id-45570" data-commid = "45570" class="upvotejs"><a class="upvote"></a> <span class="count">145</span></div></div><div class="comt-main" id="div-comment-45570"><p>在线程里，传递参数有三种方法：</p>

<p><strong>1、使用元组传递 threading.Thread(target=方法名，args=（参数1,参数2, ...）)</strong></p>


<pre>import time
import threading

def song(a,b,c):
    print(a, b, c)
    for i in range(5):
        print("song")
        time.sleep(1)
if __name__ == "__main__":
    threading.Thread(target=song,args=(1,2,3)).start()</pre>


<p><strong>2、使用字典传递 threading.Thread(target=方法名, kwargs={"参数名": 参数1, "参数名": 参数2, ...})</strong></p>
<pre>threading.Thread(target=song,kwargs={"a":1,"c":3,"b":2}).start() #参数顺序可以变</pre>

<p><strong>3、混合使用元组和字典 threading.Thread(target=方法名，args=（参数1, 参数2, ...）, kwargs={"参数名": 参数1,"参数名": 参数2, ...})</strong></p>

<pre>threading.Thread(target=song,args=(1,),kwargs={"c":3,"b":2}).start()</pre><div class="comt-meta wrapper"><span class="comt-author"><a target="_blank" href="javascript:;">Dexu</a><div class="tooltip tooltip1"><p><i class="fa fa-user" aria-hidden="true"></i>&nbsp;&nbsp;&nbsp;Dexu</p><p><i class="fa fa-envelope" aria-hidden="true"></i>&nbsp;&nbsp;724***971@qq.com</p></div></span>4年前 (2019-08-08)</div></div></li><!-- #comment-## -->
<li class="comment odd alt thread-odd thread-alt depth-1" id="comment-46110"><span class="comt-f">#0</span><div class="comt-avatar wrapper"><i style="font-size:36px;" class="fa fa-user-circle" aria-hidden="true"></i><div class="tooltip"><p><i class="fa fa-user" aria-hidden="true"></i>&nbsp;&nbsp;&nbsp;举世无双古拉顿</p><p><i class="fa fa-envelope" aria-hidden="true"></i>&nbsp;&nbsp;184***72838@163.com</p></div><div id="runoobvote-id-46110" data-commid = "46110" class="upvotejs"><a class="upvote"></a> <span class="count">161</span></div></div><div class="comt-main" id="div-comment-46110"><p>上面那个理解不了，我这个应该更容易懂:</p>
<pre>import time
import threading
# 使用 threading 模块创建线程
import queue
#优先级队列模块
#线程优先级队列(Queue)
exitFlag = 0
class myThread (threading.Thread):
    def __init__(self, threadID, name, q):
        threading.Thread.__init__(self)
        self.threadID = threadID
        self.name = name
        self.q = q
    def run(self):
        print ("开启线程：" + self.name)
        process_data(self.threadID,self.name, self.q)
        print ("退出线程：" + self.name)
def process_data(id,threadName, q):
    while not exitFlag:
        id += 1
        if id &gt;= 4:
            data = q.get()
            print ("%s processing %s" % (threadName, data))
        time.sleep(1)
threadList = ["Thread-1", "Thread-2", "Thread-3"]
nameList = ["One", "Two", "Three", "Four", "Five"]
workQueue = queue.Queue(10)
threads = []
threadID = 1
# 填充队列
for word in nameList:
    workQueue.put(word)
# 创建新线程
for tName in threadList:
    thread = myThread(threadID, tName, workQueue)
    thread.start()
    threads.append(thread)
    threadID += 1
# 等待队列清空
while not workQueue.empty():
    pass
# 通知线程是时候退出
exitFlag = 1
# 等待所有线程完成
for t in threads:
    t.join()
print ("退出主线程")
</pre>
<div class="comt-meta wrapper"><span class="comt-author"><a target="_blank" href="javascript:;">举世无双古拉顿</a><div class="tooltip tooltip1"><p><i class="fa fa-user" aria-hidden="true"></i>&nbsp;&nbsp;&nbsp;举世无双古拉顿</p><p><i class="fa fa-envelope" aria-hidden="true"></i>&nbsp;&nbsp;184***72838@163.com</p></div></span>4年前 (2019-08-26)</div></div></li><!-- #comment-## -->
<li class="comment even thread-even depth-1" id="comment-57862"><span class="comt-f">#0</span><div class="comt-avatar wrapper"><i style="font-size:36px;" class="fa fa-user-circle" aria-hidden="true"></i><div class="tooltip"><p><i class="fa fa-user" aria-hidden="true"></i>&nbsp;&nbsp;&nbsp;博大慕</p><p><i class="fa fa-envelope" aria-hidden="true"></i>&nbsp;&nbsp;ttt***q.com</p></div><div id="runoobvote-id-57862" data-commid = "57862" class="upvotejs"><a class="upvote"></a> <span class="count">41</span></div></div><div class="comt-main" id="div-comment-57862"><p>上面的太麻烦，还是我这个好理解和使用:</p>

<pre>#!/usr/bin/python

from concurrent.futures import ProcessPoolExecutor
from os import getpid as pid
from time import sleep

L = [1,2,3,4,5]

#单进程,要用至少25秒
for i in L:
    sleep(5)
    print(pid(),"已过5秒",i)

#多进程并发，5秒
def SleepPrint (in_value) :
    sleep(5)
    print(pid(),"已过5秒",in_value)
pool = ProcessPoolExecutor(5)
for i in L :
    pool.submit(SleepPrint,i)</pre><div class="comt-meta wrapper"><span class="comt-author"><a target="_blank" href="javascript:;">博大慕</a><div class="tooltip tooltip1"><p><i class="fa fa-user" aria-hidden="true"></i>&nbsp;&nbsp;&nbsp;博大慕</p><p><i class="fa fa-envelope" aria-hidden="true"></i>&nbsp;&nbsp;ttt***q.com</p></div></span>3年前 (2020-10-16)</div></div></li><!-- #comment-## -->
<li class="comment odd alt thread-odd thread-alt depth-1" id="comment-68334"><span class="comt-f">#0</span><div class="comt-avatar wrapper"><i style="font-size:36px;" class="fa fa-user-circle" aria-hidden="true"></i><div class="tooltip"><p><i class="fa fa-user" aria-hidden="true"></i>&nbsp;&nbsp;&nbsp;lijiajun</p><p><i class="fa fa-envelope" aria-hidden="true"></i>&nbsp;&nbsp;lij***un3029@gmail.com</p></div><div id="runoobvote-id-68334" data-commid = "68334" class="upvotejs"><a class="upvote"></a> <span class="count">24</span></div></div><div class="comt-main" id="div-comment-68334"><p>关于线程优先级队列（ Queue）小结：</p>

<p>首先为了体现 queue 特性，代码中理应避免使用 Lock。</p>

<p>队列之于多线程，在于多任务处理时，不便创建过多线程而消耗过量资源，因此queue模块提供了同步的，线程安全的队列类。</p>

<pre>import threading
import queue
import time


class Worker(threading.Thread):
    def __init__(self, name, queue):
        threading.Thread.__init__(self)
        self.name = name
        self.queue = queue
        self.start()  # 执行run()    
    def run(self):
        # 循环，保证接着跑下一个任务        
        while True:
            # 队列为空则退出线程            
            if self.queue.empty():
                break            
            # 获取一个队列数据
            foo = self.queue.get()
            print(self.getName() + " process " + str(foo))          
            # 延时1s模拟你要做的事情            
            time.sleep(1)
            # 任务完成            
            self.queue.task_done()


# 队列
queue = queue.Queue()
# 加入10个任务队列
for i in range(10):
    queue.put(i)
# 开3个线程
for i in range(3):
    threadName = 'Thread' + str(i)
    Worker(threadName, queue)
# 所有线程执行完毕后关闭
queue.join()</pre><div class="comt-meta wrapper"><span class="comt-author"><a target="_blank" href="javascript:;">lijiajun</a><div class="tooltip tooltip1"><p><i class="fa fa-user" aria-hidden="true"></i>&nbsp;&nbsp;&nbsp;lijiajun</p><p><i class="fa fa-envelope" aria-hidden="true"></i>&nbsp;&nbsp;lij***un3029@gmail.com</p></div></span>1年前 (2021-11-19)</div></div></li><!-- #comment-## -->
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	// 提交笔记
	var commentform=$('#commentform');
	commentform.prepend('<div id="comment-status" style="display:none;" ></div>');
	var statusdiv=$('#comment-status');
	
	commentform.submit(function(e){
		e.preventDefault();
		var noteContent = editor.getValue();
		// console.log(noteContent);
		noteContent = noteContent.replace(/<pre><code>/g,"<pre>");
		noteContent = noteContent.replace(/<\/code><\/pre>/g,"</pre>");
		
		// 系列化表单数据
		var comment_parent = 0;
		var is_user_logged_in = $("#is_user_logged_in").val();
		var comment_post_ID =  15543;
		var _wp_unfiltered_html_comment = $("#_wp_unfiltered_html_comment").val();
		var comment = noteContent;
		var author = $("#author").val();
		var url = $("#url").val();
		var email = $("#email").val();
		if(isBlank(author) && is_user_logged_in==0) {
			statusdiv.html('<p  class="ajax-error">请输入昵称！</p>').show();
		} else if(isBlank(email)  && is_user_logged_in==0) {
			statusdiv.html('<p  class="ajax-error">请输入邮箱！</p>').show();
		} else {
			// var formdata=commentform.serialize() + "&comment=" + noteContent ;
			// 添加状态信息
			statusdiv.html('<p>Processing...</p>').show();
			// 获取表单提交地址
			var formurl=commentform.attr('action');
			
			// 异步提交
			$.ajax({
					type: 'post',
					url: formurl,
					dataType:'json',
					data: {"comment_parent":comment_parent,"comment_post_ID":comment_post_ID, "_wp_unfiltered_html_comment":_wp_unfiltered_html_comment,"comment":comment,"url":url, "email":email,"author":author},
					error: function(XMLHttpRequest, textStatus, errorThrown){
					statusdiv.html('<p class="ajax-error" >数据不完整或表单提交太快了！</p>').show();
				},
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						statusdiv.html('<p class="ajax-success" >笔记已提交审核，感谢分享笔记！</p>').show();
						alert('笔记已提交审核，感谢分享笔记！');
					}else{
						statusdiv.html('<p class="ajax-error" >'+data.msg+'</p>').show();
					}
					commentform.find('textarea[name=comment]').val('');
				}
			});
			setTimeout(function(){
		        $("#submit").prop('disabled', false);
		    }, 10*1000);
		}
		return false;

	});
	$(".comt-author").click(function() {
		href = $(this).children("a").attr("href");
		if(href.indexOf("/note/")!=-1) {
			var win = window.open(href, '_blank');
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	});
	*/
	//Upvote.create('runoobvote-id', {callback: vote_callback});
	var ajaxurl = 'https://www.runoob.com/wp-admin/admin-ajax.php';
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		//console.log(data);
		_vote_action = data.action;
		id_arr = data.id.split('-');
		um_id= id_arr[2];
		//console.log(um_id);
		
		var re = /^[1-9]+/;
		if (re.test(um_id)) { 
			var ajax_data = {
				_vote_action: _vote_action,
				action: "pinglun_zan",
				um_id: um_id,
				um_action: "ding"
			};
			//console.log(ajax_data);
			$.post(ajaxurl,ajax_data,function(status){
				//if(status.vote_num>999) {
				//	_voteHtml = '<span style="display: block; text-align: center;font-size: 20px; color: #6a737c; margin: 8px 0;">'+kFormatter(status.vote_num) +'</span>';
				//	$("#runoobvote-id-" + um_id + " .count").hide().after(_voteHtml);
				//}
				
			});
		}
	};
	if($('#comments').length && $('.upvotejs').length){
		$('.upvotejs').upvote({id: 15543, callback: callback});
	
		$.post(ajaxurl,{"action":"pinglun_zan","postid":15543},function(data){  
			$(data).each(function(key,value) {
				$("#runoobvote-id-" + value.commid + " .upvote").addClass(value.upvotejs_class);
				$("#runoobvote-id-" + value.commid + " .downvote").addClass(value.downvote_class);
				$("#runoobvote-id-" + value.commid + " .count").text(value.upvote_count);
			})
		},'json');
		
	}
	
	
});
function isBlank(str) {
    return (!str || /^\s*$/.test(str));
}
function kFormatter(num) {
	// return num;
    return Math.abs(num) > 999 ? Math.sign(num)*((Math.abs(num)/1000).toFixed(1)) + 'k' : Math.sign(num)*Math.abs(num)
}

</script>

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